Motorcycle gas tank



FIG. 1 is a perspective view showing my new design;

FIG. 2 is a top view;

FIG. 3 is a right side view, the left side being a mirror image thereof;

FIG. 4 is a bottom view;

FIG. 5 is a front view; and,

FIG. 6 is a back view of the design.

The broken lines show environment and are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a motorcycle gas tank, as shown and described. 